Eltrombopag (Promacta™)

OncoLink Last Modified: August 21, 2011

Pronounced: el-TROM-boe-pagClassification: Antithrombin Agent

About Eltrombopag

Eltrombopag is a man-made protein used to treat a low platelet count (thrombocytopenia) in adults that is caused by idiopathic thrombocytopenic purpura (also called ITP). Eltrombopag is a thrombopoietin receptor agonist that stimulates bone marrow cells to produce platelets.

Eltrombopag may only be prescribed and distributed by healthcare providers who are certified by the Promacta CARES program, which oversees the distribution and safe use of eltrombopag. Patients who receive the drug will also be enrolled in and monitored by the Promacta CARES program.

How to Take Eltrombopag

Eltrombopag is given in a pill form once a day. The recommended starting dose is 50mg a day. Patients of East Asian ancestry or those with liver problems will be started at a lower dose due to the risk of liver toxicity. The medication should be taken on an empty stomach (1 hour before or 2 hours after a meal). Do not consume any foods, supplements or antacids that contain iron, calcium, aluminum, magnesium, selenium or zinc for at least 4 hours before or after taking the medication. These compounds significantly reduce the absorption of eltrombopag. Your platelet count will be checked weekly and the dose of medication adjusted accordingly, to a maximum of 75mg a day. In addition, liver function will be tested periodically to evaluate for toxicity.

Possible Side Effects of Eltrombopag

There are a number of things you can do to manage the side effects of Eltrombopag. Talk to your doctor or nurse about these recommendations. They can help you decide what will work best for you. These are some of the most common side effects:

Liver Function Changes

In studies, some patients developed liver function abnormalities. Your healthcare team will monitor your liver function using blood tests. You should notify your healthcare team right away if you notice a yellowing of the skin or whites of the eyes (jaundice), darkening of the urine, unusual tiredness or pain in the right upper stomach area, as these can be signs of liver problems.

Bone Marrow Changes

Long term use of eltrombopag may cause changes in your bone marrow. These can include an increase in reticulin. Increased reticulin is unlikely to cause problems, but it is not known if this can lead to a more serious condition called bone marrow fibrosis, which is a scarring of the bone marrow, causing it to produce fewer blood cells. Your healthcare provider will monitor your blood tests for abnormalities that could signify changes in the bone marrow.

Worsening of the Platelet Count After Stopping the Medication

In clinical trials, some patients experienced lower platelet counts when the medication was stopped than they had before taking the medication. This side effect is most likely to occur shortly after stopping eltrombopag and may last about 1 month. This lower platelet count increases the risk of bleeding, so precautions should be taken and any bruising or bleeding should be reported to your healthcare provider.

Muscle or Joint Pain/Aches and Headache

Applying a heating pad to aching muscles or joints may provide some relief. Your doctor or nurse can recommend medication and other strategies to relive pain. Also view OncoLink's page on pain management.

Blood Clots

Your healthcare provider will monitor your platelet count to attempt to prevent it from getting too high. A high platelet count can increase the risk of developing a blood clot. Blood clots can occur anywhere in the body. They occur most frequently in the calves (leg) or the lungs. People at higher risk for developing blood clots include those with a family history of blood clots, smokers, those who have an inactive lifestyle, older patients, and those with other medical problems.

Signs of a blood clot in the leg may include any of the following: leg pain, warmth, swelling of one leg more than the other. Signs of a blood clot in the lung could include: fever, shortness of breath that comes on you very quickly, racing heart and chest pain (that tends to be worse when you take a deep breath).

If you have any of these signs or symptoms of blood clots, you will need to be seen immediately so that you can be treated with blood thinners. Call your doctor or nurse.

Other Side Effects

The following side effects were also reported in clinical trials: development of cataracts, nausea/vomiting, dyspepsia and heavy menstrual cycles.